Police have begun searching a landfill north of Christchurch as part of their investigation into missing builder Michael McGrath, who was last seen more than two weeks ago.
Officers had previously indicated the Kate Valley refuse centre at Waipara, 70km north of Christchurch, would be part of their search.
They were set to begin work there today, helped by 20 army personnel.
Detective Inspector Darryl Sweeney said the search would be a challenging task and was expected to take at least two weeks.
He said police were fortunate to have the army's personnel and logistical expertise.
The work is the latest in a number of land, water and property searches in the inquiry into Mr McGrath's disappearance.